watertight

• POS: Adjective
• HYPHEN: wa=ter=tight

OXFORD DICTIONARY

watertight, adj.
1 (of a joint, container, vessel, etc.) closely fastened or fitted or made so as to prevent the passage of water.
2 (of an argument etc.) unassailable.

THESAURUS

watertight

airtight, ballproof, bold, bombproof, bulletproof, burglarproof, close, compact, corrosionproof, dampproof, dripproof, dustproof, dusttight, fast, fire-resisting, fireproof, firm, fit for sea, flameproof, floodproof, foolproof, gasproof, gastight, hermetic, hermetically sealed, holeproof, impervious to, leakproof, lightproof, lighttight, moistureproof, noiseproof, oilproof, oiltight, proof, proof against, punctureproof, rainproof, raintight, resistant, rustproof, sea-kindly, sealed, seaworthy, seepproof, shatterproof, shellproof, shut fast, smokeproof, smoketight, snug, soundproof, staunch, stiff, stormproof, stormtight, tender, tight, water-repellant, waterproof, weatherly, weatherproof, windproof, windtight